Cotyledon orbiculata var. oblonga 'Undulata' (Silver Ruffles) - An upright sparingly-branched succulent 18 to 24 inches tall with very attractive dumpling-shaped leaves that are upwardly inclined and are tightly overlapped with all parts of the leaves covered with a white powder, likened by some to "icing sugar", and have strongly undulating flat margins. In summer appear the 1 foot tall inflorescences topped with dangling reddish-orange flowers. Looks best if grown in full sun, watered sparingly and where overhead watering can be avoided as this washes the waxy bloom from the leaf surface. Should prove hardy to around 25 °F. Though not as easy to grow as typical Cotyledon orbiculata, its interesting foliage and large flowers makes this a worthwhile plant for a special pot or in combination with other succulents. Can become a little leggy so take cuttings often to keep plant more compact and to make new plants. Our original plants from the Huntington Botanic Garden (HBG 89167) as Cotyledon undulata, though this name has been combined into Cotyledon orbiculata var. oblonga in a recent treatment of the genus by Ernst van Jaarsveld so we currently list this plant as the cultivar 'Undulata'. The reason for this name for the genus is a complicated story. The plant, Wall Pennywort or Navelwort, (Umbilicus rupestris) was previously included in the genus. In medieval times, and in homeopathic medicine, this plant was/is commonly known as Cotyledon so this name stuck with the genus, even though the plant it was named for did not. The name originated from the Greek word 'kotyledon' or 'kotyle' meaning "cupped", "hollowed" or "a cavity". The specific epithet "undulata" that was originally used for this plant is Latin meaning "wavy" or undulate in reference to the leaf margin.
This description is based on research and observations made of this plant as it grows in our nursery, in our nursery garden and in other gardens that we have visited. We also try to incorporate comments received from others and appreciate getting feedback of any kind from those who have any additional information about this plant, particularly if they disagree with what we have written or if they have additional cultural tips that would aid others in growing Cotyledon orbiculata 'Undulata'.